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Resoldering istick tc 100w switch?

Synphul

Gold Contributor
Member For 4 Years
Any suggestions for what type solder to use to repair soldered connections in mods?

My istick tc 100w started acting up, took it apart and discovered that the soldered connections between the main pcb and switch pcb had cracked. Chinese engineering at its finest, nothing else secures the two pcb boards beyond the soldered points which are all along one side creating a hinged effect. Off center pressure can tilt the smaller pcb for the switch a bit and allows the solder to crack, two of 4 connections are cracked.

My hopes are to pick up a cheap soldering pen in the 40-60w range but not sure which solder they used. If all goes well just a touch of heat may allow it to reflow together using theirs. Otherwise I'll have to add a little bit but not overly keen on mixing solders.

Here's a crappy pic but the idea is there. The red arrows point to where the soldered joints need repaired, the yellow lines are where I'm hoping to add a bit of super glue or something to bolster the switch pcb and take some of the pressure off the soldered joints.

afdbb9c824f94da18a912f3b4f93ea2c.png


Thanks for suggestions.
 

kevin littell

Bronze Contributor
Member For 3 Years
Member For 2 Years
ECF Refugee
Use resin core NOT plumbing solder, get at least a 50 watt iron (theory is they heat the connector up higher but as not as long) and use a piece of metal like a screwdriver on scissors to heat sink it once the solder solidifies a bit. Ive been known to put a precision screwdriver in the freezer and yank it out just before I made the solder joint.

With solder less is better.

Also, Too secure electronic PCB's I usually use rtv silicon....It hardens, its an insulator and most importantly, its removable.
 

Synphul

Gold Contributor
Member For 4 Years
Thanks kevin, I ordered a 60w adjustable temp iron (hopefully it works right) and it comes with some resin core solder. You mentioned chilling a screwdriver, to immediately chill the solder and solidify it once it's flowed into place? I've got a small pocket screwdriver I could use to do that. I've soldered bigger stuff but didn't have to be as precise, nothing this tiny. Previous solder jobs were a lot more forgiving lol.
 

kevin littell

Bronze Contributor
Member For 3 Years
Member For 2 Years
ECF Refugee
Thanks kevin, I ordered a 60w adjustable temp iron (hopefully it works right) and it comes with some resin core solder. You mentioned chilling a screwdriver, to immediately chill the solder and solidify it once it's flowed into place? I've got a small pocket screwdriver I could use to do that. I've soldered bigger stuff but didn't have to be as precise, nothing this tiny. Previous solder jobs were a lot more forgiving lol.

Yes....the longer the works stay heated up the more likely there is to be heat damage. Make sure your joints are good and when the solder solidify s, tap it with something to sink the heat away from the electronics.
 

Synphul

Gold Contributor
Member For 4 Years
Tried that, the switch still isn't working properly. I wanted to give eleaf the benefit of the doubt but it turns out to be another cheap chinese piece of fuck. People may hate the hell out of cigs but they have one key thing going for them. They work. More than I can say for this cheap chinese 'tech'. It's no surprise they offer shit for warranty on them. I'd be scared to try and warranty that garbage too.
 

kevin littell

Bronze Contributor
Member For 3 Years
Member For 2 Years
ECF Refugee
I have an Eleaf 20w that I paid 30 bucks for 2 years ago that is still just a chugging away....Of course, I dont have anything I run that low anymore......


Its luck of the draw, I remember paying 90 bucks for a 10 watt VV "pipe bomb" that quit because of the 20 cent micro switch....And I retired 2 EGO 18650 mods cause the buttons didnt click anymore and I deemed them unsafe.


Those Eleafs aren't real junky but the switch is the Achilles heal. Hit the interwebs and see if you can find a replacement....You have the tools now!!!


And check to see if you cold soldered them....That will sometimes offer a high resistance to the circuit.
 

Synphul

Gold Contributor
Member For 4 Years
The device comes on when a battery is installed but the button clicks and does squat. I'd say luck of the draw but if that's the case I'd have won the lotto by now. Buying 5-6 of the same device and eventually hitting a problem is one thing, randomly buying one of thousands produced and it's shit says more likely than not 50% or more are garbage. Cheap chinese engineering (no wonder they have to rip everyone off).

At this point I've dumped $30 into a mod, $20 into a tool I had no use for other than try to repair said mod, potentially god knows how much more for another shit mod.. on the other hand, I've still got packs of smokes laying around and they work right outta the box. I didn't get into vaping for additional headaches and bullshit or another unnecessary hobby. Nor to get an electrical engineering degree to fix shit bought broken.

I guess my pov on it is, why keep buying more unwarranted crap and reward them? If you go to a donut shop and get shitty donuts you don't go back and buy more. Not to mention with all the fda deeming regs, they want a photo id, ssn, your identity packaged in a kit waiting to be ripped off, an anal probe, retinal scan and everything else. Or I can walk into a gas station and pick up a carton without even getting carded.
 

kevin littell

Bronze Contributor
Member For 3 Years
Member For 2 Years
ECF Refugee
I went thru this stage also...Spent 2 years vaping a good Nemesis Mechanical clone on a Kayfun light V2...Whole rig plus wire and cotton cost me 45 bucks because I wasn't going back to the stinkies and wasn't gonna spend 100 bucks on another Tube mod to have a 5 penny unreachable micro switch go bad. Cold turkey quitting is not an option either.But the prices on the regulated mods dropped significantly and I refused to spend more then 40 bucks on one....I've had the Eleaf 20 watt, a Coolfire 4 by Innokin and both are still vaping.My pov is 40 bucks every 4-6 months for a mod is still cheaper then lung cancer and marginally cheaper then the smokes.

Have a Volt Ohm meter?
 

Synphul

Gold Contributor
Member For 4 Years
I've got a voltmeter yes. Not sure how to test the switch though since I have no clue what the specs are for it, what factory readings should be. It's two pcb's connected via blobs of solder so I have no clue without a schematic what the traces on the pcb connect to. The two positives after repair show continuity but I can't tell if there's a microscopic bleed from the solder or if somewhere else on the board there's a trace that's causing the loop. No way to tell if that's the fault or if it's normal.

Honestly not worth fucking with at this point, shoulda thrown in the towel rather than dumping more money into repair tools I didn't need. At $30 it's kinda disposable but what I consider disposable every 6-12mo, not every 2mo. That's just ridiculous.
 

kevin littell

Bronze Contributor
Member For 3 Years
Member For 2 Years
ECF Refugee
Agreed.....I gave 80 bucks for a tube mod, 2 months later the switch quit. I was so mad I bought a carton.

3 weeks later I was wheezing...


2 wire leads on the board?


Send a better picture of both sides of the switch daughter board and one focused on the back of the board where the switch is??
 

Zamazam

Evil Vulcan's do it with Logic
VU Donator
Platinum Contributor
Member For 5 Years
15-20W pencil Iron. Rosin core solder, 100% Tin.
 

saytar

Bronze Contributor
Member For 3 Years
Member For 2 Years
Member For 1 Year
15-20W pencil Iron. Rosin core solder, 100% Tin.
28-30 gauge solder........very thin solder............silver solder works too (if you spend a bit more).....just DON'T use any acid based core, not on ANY electronics circuitry.

Another thing....tin ends of wire, tin pads, let cool............place tinned wire against tinned circut pad, then just touch wire with iron until solder flows and IMMEDIATELY remove heat............let cool naturally (a light blowing with your breath on the connection is enough). Cooling a soldered connection too quickly will result in a HIGH resistance or cold solder joint.......a cold joint looks dull and usually will leave an open connection even if it appears soldered...........and will not conduct electricity, especially the extremely low voltage and current passing thru the switch..thus a switch with a cold joint will not allow the circuit connection to be completed......

You can check this with a simple ohm meter....if it reads a short the switch is working, an infinite reading (an open) indicates it is not working.......a quick simple and dirty method is to use a short piece of wire and short across the switch connections (be careful to not touch any other connections, just the two for the switch), if the mod fires the switch is bad...if it doesn't ......your screwed. I suspect that the copper foil on the circuit board is broken or cracked close or near to the pad you soldered on...a magnifying glass and strong light will usually revel this....

A properly soldered connection is bright and shiny in appearance.........practice a bit on something non critical...soldering properly is an art form.............learned this from years of repairing and replacing 48, 64 and 128 pin flat pak IC chips in consumer electronics equipment......

Solder removal wick ( which is rosin treated braided copper wire) is the best for removing excessive solder from delicate circuit boards and connections, as the wick will provide some limited heat sinking for your small board copper pads (which are easy to overheat and pull loose from the substrate of the board).........solder suckers are only good for removing solder from larger thru board connectors and are generally a major pain in the ass to use........
 

Synphul

Gold Contributor
Member For 4 Years
Thanks for the advice saytar, a lot of info there.

The place that needs soldered has no wires at all. It's a contact pad on the switch pcb and a contact pad on the main board. With one resting on top of the other, the connection between the two (imagine a stair step between the two pcb's) is literally just a blob of solder. It's not a wire or a through connection point or anything else, it's small blobs of solder about twice the size of a ballpoint pen tip connecting traces between the two pcb's.

I'm not sure about the board but the soldered spots are visibly cracked. That's what I tried to reflow to repair. I could see the hairline crack in 2 of the 4 solder points.
 

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